1 /* $OpenBSD: dd.c,v 1.15 2007/11/10 13:45:17 chl Exp $ */ 2 /* $NetBSD: dd.c,v 1.6 1996/02/20 19:29:06 jtc Exp $ */ 3 4 /*- 5 * Copyright (c) 1991, 1993, 1994 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Keith Muller of the University of California, San Diego and Lance 10 * Visser of Convex Computer Corporation. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 static char copyright[] = 39 "@(#) Copyright (c) 1991, 1993, 1994\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 #if 0 45 static char sccsid[] = "@(#)dd.c 8.5 (Berkeley) 4/2/94"; 46 #else 47 static char rcsid[] = "$OpenBSD: dd.c,v 1.15 2007/11/10 13:45:17 chl Exp $"; 48 #endif 49 #endif /* not lint */ 50 51 #include <sys/param.h> 52 #include <sys/stat.h> 53 #include <sys/ioctl.h> 54 #include <sys/mtio.h> 55 56 #include <ctype.h> 57 #include <err.h> 58 #include <errno.h> 59 #include <fcntl.h> 60 #include <signal.h> 61 #include <stdio.h> 62 #include <stdlib.h> 63 #include <string.h> 64 #include <unistd.h> 65 66 #include "dd.h" 67 #include "extern.h" 68 69 static void dd_close(void); 70 static void dd_in(void); 71 static void getfdtype(IO *); 72 static void setup(void); 73 74 IO in, out; /* input/output state */ 75 STAT st; /* statistics */ 76 void (*cfunc)(void); /* conversion function */ 77 size_t cpy_cnt; /* # of blocks to copy */ 78 u_int ddflags; /* conversion options */ 79 size_t cbsz; /* conversion block size */ 80 size_t files_cnt = 1; /* # of files to copy */ 81 const u_char *ctab; /* conversion table */ 82 83 int 84 main(int argc, char *argv[]) 85 { 86 jcl(argv); 87 setup(); 88 89 (void)signal(SIGINFO, summaryx); 90 (void)signal(SIGINT, terminate); 91 92 atexit(summary); 93 94 if (cpy_cnt != (size_t)-1) { 95 while (files_cnt--) 96 dd_in(); 97 } 98 99 dd_close(); 100 exit(0); 101 } 102 103 static void 104 setup(void) 105 { 106 #ifndef NO_CONV 107 u_int cnt; 108 #endif 109 110 if (in.name == NULL) { 111 in.name = "stdin"; 112 in.fd = STDIN_FILENO; 113 } else { 114 in.fd = open(in.name, O_RDONLY, 0); 115 if (in.fd < 0) 116 err(1, "%s", in.name); 117 } 118 119 getfdtype(&in); 120 121 if (files_cnt > 1 && !(in.flags & ISTAPE)) 122 errx(1, "files is not supported for non-tape devices"); 123 124 if (out.name == NULL) { 125 /* No way to check for read access here. */ 126 out.fd = STDOUT_FILENO; 127 out.name = "stdout"; 128 } else { 129 #define OFLAGS \ 130 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 131 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 132 /* 133 * May not have read access, so try again with write only. 134 * Without read we may have a problem if output also does 135 * not support seeks. 136 */ 137 if (out.fd < 0) { 138 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 139 out.flags |= NOREAD; 140 } 141 if (out.fd < 0) 142 err(1, "%s", out.name); 143 } 144 145 getfdtype(&out); 146 147 /* 148 * Allocate space for the input and output buffers. If not doing 149 * record oriented I/O, only need a single buffer. 150 */ 151 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 152 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) 153 err(1, "input buffer"); 154 out.db = in.db; 155 } else if ((in.db = 156 malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL || 157 (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) 158 err(1, "output buffer"); 159 in.dbp = in.db; 160 out.dbp = out.db; 161 162 /* Position the input/output streams. */ 163 if (in.offset) 164 pos_in(); 165 if (out.offset) 166 pos_out(); 167 168 /* 169 * Truncate the output file; ignore errors because it fails on some 170 * kinds of output files, tapes, for example. 171 */ 172 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK)) 173 (void)ftruncate(out.fd, out.offset * out.dbsz); 174 175 /* 176 * If converting case at the same time as another conversion, build a 177 * table that does both at once. If just converting case, use the 178 * built-in tables. 179 */ 180 if (ddflags & (C_LCASE|C_UCASE)) { 181 #ifdef NO_CONV 182 /* Should not get here, but just in case... */ 183 errx(1, "case conv and -DNO_CONV"); 184 #else /* NO_CONV */ 185 if (ddflags & C_ASCII || ddflags & C_EBCDIC) { 186 if (ddflags & C_LCASE) { 187 for (cnt = 0; cnt < 0377; ++cnt) 188 casetab[cnt] = tolower(ctab[cnt]); 189 } else { 190 for (cnt = 0; cnt < 0377; ++cnt) 191 casetab[cnt] = toupper(ctab[cnt]); 192 } 193 } else { 194 if (ddflags & C_LCASE) { 195 for (cnt = 0; cnt < 0377; ++cnt) 196 casetab[cnt] = tolower(cnt); 197 } else { 198 for (cnt = 0; cnt < 0377; ++cnt) 199 casetab[cnt] = toupper(cnt); 200 } 201 } 202 203 ctab = casetab; 204 #endif /* NO_CONV */ 205 } 206 207 /* Statistics timestamp. */ 208 (void)gettimeofday(&st.startv, (struct timezone *)NULL); 209 } 210 211 static void 212 getfdtype(IO *io) 213 { 214 struct mtget mt; 215 struct stat sb; 216 217 if (fstat(io->fd, &sb)) 218 err(1, "%s", io->name); 219 if (S_ISCHR(sb.st_mode)) 220 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 221 else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) 222 io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */ 223 } 224 225 static void 226 dd_in(void) 227 { 228 ssize_t n; 229 230 for (;;) { 231 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 232 return; 233 234 /* 235 * Zero the buffer first if sync; if doing block operations 236 * use spaces. 237 */ 238 if (ddflags & C_SYNC) { 239 if (ddflags & (C_BLOCK|C_UNBLOCK)) 240 (void)memset(in.dbp, ' ', in.dbsz); 241 else 242 (void)memset(in.dbp, 0, in.dbsz); 243 } 244 245 n = read(in.fd, in.dbp, in.dbsz); 246 if (n == 0) { 247 in.dbrcnt = 0; 248 return; 249 } 250 251 /* Read error. */ 252 if (n < 0) { 253 /* 254 * If noerror not specified, die. POSIX requires that 255 * the warning message be followed by an I/O display. 256 */ 257 if (!(ddflags & C_NOERROR)) 258 err(1, "%s", in.name); 259 warn("%s", in.name); 260 summary(); 261 262 /* 263 * If it's not a tape drive or a pipe, seek past the 264 * error. If your OS doesn't do the right thing for 265 * raw disks this section should be modified to re-read 266 * in sector size chunks. 267 */ 268 if (!(in.flags & (ISPIPE|ISTAPE)) && 269 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 270 warn("%s", in.name); 271 272 /* If sync not specified, omit block and continue. */ 273 if (!(ddflags & C_SYNC)) 274 continue; 275 276 /* Read errors count as full blocks. */ 277 in.dbcnt += in.dbrcnt = in.dbsz; 278 ++st.in_full; 279 280 /* Handle full input blocks. */ 281 } else if (n == in.dbsz) { 282 in.dbcnt += in.dbrcnt = n; 283 ++st.in_full; 284 285 /* Handle partial input blocks. */ 286 } else { 287 /* If sync, use the entire block. */ 288 if (ddflags & C_SYNC) 289 in.dbcnt += in.dbrcnt = in.dbsz; 290 else 291 in.dbcnt += in.dbrcnt = n; 292 ++st.in_part; 293 } 294 295 /* 296 * POSIX states that if bs is set and no other conversions 297 * than noerror, notrunc or sync are specified, the block 298 * is output without buffering as it is read. 299 */ 300 if (ddflags & C_BS) { 301 out.dbcnt = in.dbcnt; 302 dd_out(1); 303 in.dbcnt = 0; 304 continue; 305 } 306 307 if (ddflags & C_SWAB) { 308 if ((n = in.dbcnt) & 1) { 309 ++st.swab; 310 --n; 311 } 312 swab(in.dbp, in.dbp, n); 313 } 314 315 in.dbp += in.dbrcnt; 316 (*cfunc)(); 317 } 318 } 319 320 /* 321 * Cleanup any remaining I/O and flush output. If necessary, output file 322 * is truncated. 323 */ 324 static void 325 dd_close(void) 326 { 327 if (cfunc == def) 328 def_close(); 329 else if (cfunc == block) 330 block_close(); 331 else if (cfunc == unblock) 332 unblock_close(); 333 if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) { 334 if (ddflags & (C_BLOCK|C_UNBLOCK)) 335 memset(out.dbp, ' ', out.dbsz - out.dbcnt); 336 else 337 memset(out.dbp, 0, out.dbsz - out.dbcnt); 338 out.dbcnt = out.dbsz; 339 } 340 if (out.dbcnt) 341 dd_out(1); 342 } 343 344 void 345 dd_out(int force) 346 { 347 static int warned; 348 size_t cnt, n; 349 ssize_t nw; 350 u_char *outp; 351 352 /* 353 * Write one or more blocks out. The common case is writing a full 354 * output block in a single write; increment the full block stats. 355 * Otherwise, we're into partial block writes. If a partial write, 356 * and it's a character device, just warn. If a tape device, quit. 357 * 358 * The partial writes represent two cases. 1: Where the input block 359 * was less than expected so the output block was less than expected. 360 * 2: Where the input block was the right size but we were forced to 361 * write the block in multiple chunks. The original versions of dd(1) 362 * never wrote a block in more than a single write, so the latter case 363 * never happened. 364 * 365 * One special case is if we're forced to do the write -- in that case 366 * we play games with the buffer size, and it's usually a partial write. 367 */ 368 outp = out.db; 369 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) { 370 for (cnt = n;; cnt -= nw) { 371 nw = write(out.fd, outp, cnt); 372 if (nw <= 0) { 373 if (nw == 0) 374 errx(1, "%s: end of device", out.name); 375 if (errno != EINTR) 376 err(1, "%s", out.name); 377 nw = 0; 378 } 379 outp += nw; 380 st.bytes += nw; 381 if (nw == n) { 382 if (n != out.dbsz) 383 ++st.out_part; 384 else 385 ++st.out_full; 386 break; 387 } 388 ++st.out_part; 389 if (nw == cnt) 390 break; 391 if (out.flags & ISCHR && !warned) { 392 warned = 1; 393 warnx("%s: short write on character device", 394 out.name); 395 } 396 if (out.flags & ISTAPE) 397 errx(1, "%s: short write on tape device", out.name); 398 } 399 if ((out.dbcnt -= n) < out.dbsz) 400 break; 401 } 402 403 /* Reassemble the output block. */ 404 if (out.dbcnt) 405 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 406 out.dbp = out.db + out.dbcnt; 407 } 408